In a mixer with a large bowl, cream together butter and sugar until smooth. Beat in eggs and vanilla. In another bowl, sift together the flour, baking powder, and salt. Slowly add this to the wet mixture until combined completely. Cover and chill dough for at least an hour or overnight. If you are preparing this for a couple of days before, remove from bowl and form into balls and wrap in plastic wrap.2. While the dough is chilling, hand whisk water and meringue powder for 30 seconds. Add cream of tartar and mix for another 30 seconds. With a stand mixer and fitted with a paddle, mix the powdered sugar with the other ingredients for 10 minutes (yes, exactly 10 minutes). Add vanilla to the mixture.
Preheat oven to 400 Degrees F. Roll out the dough on a floured surface to ¼-1/2 inch thickness. Cut the dough into shapes using cookie cutters. Place cookies 1 inch apart on a greased cookie sheet. Put a pinch of granulated sugar on each top.
Bake for 6-8 minutes in the preheated oven. They are done when the edges are lightly brown and the center is still white. Let the cookies sit on the pan for 1 minute after taking them out of the oven, then transfer to wire rack to cool completely.
Separate the royal icing into small bowls depending on how many colors you want. Dye the icing and transfer to piping bags (or small sandwich zip locks).
Begin icing the outline of the cookies, then fill in the center. Use a small butter knife to smooth the icing out if you wish. Let the cookies dry completely before moving them. Stack them up, package them or layer them on a platter, grab some milk and ENJOY!
Notes
Recipe for Royal Icing from Sweetopia.
Recipe by Laugh Eat Learn at https://laugheatlearn.com/holiday-sugar-cookies/